Well. I too would recommend the F1. But then I have 26 of them already

I know people dont like the new zytel sheath because it might look ugly. Well, it is practical and fits very nicely in Molle wests.
The closed leather sheath for the F1 is for people who carry the knife more than they use it (turn the flap over and tuck it between the belt and your pants and it stays open). The open leather is more for camping use and such. A classic way of carrying a knife.
The zytel sheath are for hunters, who gets their knife full of blood and stuff, and for militar people who want a sheath that can take a beating. It also holds the thin sharpener glued onto it.
How to attach an F1 to a Molle:
1. Hold the sheath on the west where you want it.
2. For handle up, move the sheath two straps up from your desired position. Inverted - two straps down.
3. Press the sheath inside the straps you just passed. It will fit nicely.
4. Now you will have one strap just between the top of the sheath and the retaining strap. Press the whole belt and ret-strap part under that strap and the next one.
Done.
Now you will have as follows:
Under the top strap- top of belt thing.
Retainer strap
Under second from top - belt thing.
Opening of sheath
three from top - behind sheath
Under four and five from top - bottom of sheath.
Inverted is same, but opposite.
I do not have a molle west so I tested this on the backside of a LMF II but I hope it works in reality as well.
Anyone who understands my idea and have a west could please post a picture of it for real.